adding logic to select the first available challenge if the default challenge is not available. fixes #290
adding logic to select the first available challenge if the default challenge is not available. fixes #290

osmlab/maproulette,mvexel/maproulette,osmlab/maproulette,mvexel/maproulette,Crashfreak/maproulette,osmlab/maproulette,Crashfreak/maproulette,Crashfreak/maproulette,mvexel/maproulette,osmlab/maproulette,Crashfreak/maproulette,mvexel/maproulette